1. Field of the Invention
The present invention relates to prefabricated building elements having surface elements applied thereto for use in structural engineering and more particularly for use in constructing roofs, ceilings, floors, walls or the like. The invention further relates to a method for producing structural building units with even large sized surface slabs and high resistance against torsion and vibration loads.
2. Description of the Related Art
Heretofore, building blocks and the like intended to have a finally designing surface have been made by disposing facing slabs onto mortar or a matrix with adhesive layer. For avoidance of condensed moisture and frost damages, building blocks with rear ventilated outer faces are generally known, which are mounted on anchoring constructions provided at raw buildings under high labour and material expense. Building elements are also known having a central portion including channels for utilities and a visible slab hingedly fixed to the central element allowing convenient access to utilities.
Such building elements are subject to the objection that the slabs are not permanently adhered to the blocks by using mortar and can be knocked off in handling, or fall off upon weathering of the mortar. Securing facing slabs to a concrete block by embedding the same in a matrix of polyester resin or the like without providing any rear ventilation may result as vapours fumes during heat influence. Furthermore this method hinders any air transmission so that unhealthy room climate will result when constructing an inside wall. At the opposite sides of a central element no constructive precautions are provided for development of counter forces against torsion- and vibration loads effecting on adhesive joints or other anchoring means between central element and surface slabs. There is the further objection that the anchoring means and the adhesive structure do little, if anything, to build up a durable compound between large sized building elements such as room high elements or ceiling elements with wide span showing large sized surface slabs such as marble slabs or the like. Such elements would be desireable for architectonic planning and reduction of overall building time. The compound of large sized building elements has to be resistant against high pressure-, torsion- and vibration loads dynamically stressing the adhesive joint between central element and surface slabs. During evasive movements of surface slabs and central element these loads effect as destabilizing shearing stresses on adhesive joints. At cracking of adhesive joints, the compound rapidly looses hold and the surface slabs are exposed to splitting up danger.